The Russians are charged with conspiracy to murder Sergei Skripal and the attempted murder of Skripal, his daughter and Nick Bailey, a police officer who was taken ill while attending to the Skripals.
"CCTV shows them in the vicinity of Mr Skripal's house and we believe that they contaminated the front door with Novichok", Basu said.
"We have full confidence in the British assessment that the two suspects were officers from the Russian military intelligence service, also known as the GRU, and that this operation was nearly certainly approved at a senior government level".
"The GRU is a highly disciplined organisation with a well-established chain of command", she said. "It was nearly certainly also approved outside the GRU at a senior level of the Russian state".
A photo made available by the London Metropolitan Police showing both suspects at Salisbury train station on March 4.
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He said forensic teams were on the scene and investigators were trying to piece together a timeline of events. Maria Manfredini, a long-term resident in the area, described the incident as "tragic on every level".
A RUSSIAN spy wanted for the attempted murder of Sergei Skripal reportedly had visited Britain nearly exactly one year before the Novichok attack in Salisbury.
Moscow said pointing the finger at the Kremlin was "unacceptable". "I don't understand why this was done and what sort of signal the British side is sending". The affair has worsened Russian relations with the West, already under strain over Ukraine, Syria and other issues.
US Ambassador Nikki Haley said everyone should be "chilled to the bone" with the findings.
Britain has called a United Nations Security Council meeting for Thursday to discuss the Novichok poisoning case.
But assistant police commissioner Neil Basu conceded it was "very, very unlikely" police would be in a position to arrest them any time soon.
Mrs May said 250 detectives had trawled through 11,000 hours of CCTV and taken more than 1400 statements to come to their conclusion.
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It also said Syrian forces have used chemical weapons, including chlorine, more than two dozen times during the war. Mr Putin said Russian Federation would continue its fight against "terrorists" in Idlib province.
There is now sufficient evidence to charge Alexander Petrov and Ruslan Boshirov over the suspected nerve agent attack in the city of Salisbury in early March, British public broadcaster BBC reported on Wednesday, citing Scotland Yard and the Crown Prosecution Service (CPS).
Mr Basu would not say whether police believe the suspects worked for Russian security services but, he said, "this was a sophisticated attack across borders". They spent weeks hospitalized in critical condition and are now recovering in a secret location for their own protection.
The following day, Mar 3, they travelled from Waterloo to Salisbury, arriving at around 2:25pm and leaving at 4:10pm on what was a particularly cold weekend, with heavy snow in the cathedral city. They stayed in a hotel in London - where traces of Novichok were also found - and made two trips to Salisbury. They are also charged with illegal use and possession of a chemical weapon.
Hemming said Britain would not be asking Russian Federation to extradite the men because that country's constitution does not permit extradition of its own nationals.
Authorities said they were making the announcement because they had gathered enough evidence to implicate Petrov and Boshirov in the attempts against the Skripals in March.
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Known for songs like "Donald Trump" (2011), Miller has struggled with substance abuse and legal issues over the years. That's fine, that's good, that's life. "Pls (sic) take care of yourself", she wrote in a message to Mac .
Calling the poisoning a "sickening and despicable" attack, Javid said it was "unequivocally, crystal-clear this was the act of the Russian state - two Russian nationals sent to Britain with the sole goal of carrying out a reckless assassination attempt".